In a spatial light modulator display, light from a backlight may be directed at and spatially modulated by a display modulation layer to provide an image to the viewer. In such a display, the backlight may have an array of light sources (e.g. an array of light-emitting diodes (LEDs)) and the display modulation layer may have an array of pixels (e.g. liquid crystal display (LCD) pixels). For dual modulation displays, the LEDs may be driven to spatially modulate the intensity of light directed at the display modulation layer and the LCD pixels may be driven to modulate the amount of light transmitted through the pixels. Some examples of dual modulation displays are described in: U.S. Pat. No. 6,891,672 issued 10 May 2005 and entitled “High Dynamic Range Display Devices”, U.S. Pat. No. 7,403,332 issued 22 Jul. 2008 and entitled “High Dynamic Range Display Devices”, and United States Patent Application Publication No. 2008/0180466 published 31 Jul. 2008 and entitled “Rapid Image Rendering on Dual-Modulator Displays”.
Drive values are generated based on image data, and are output to the backlight and the display modulation layer to control the image displayed on the display. For example, where the light sources are LEDs and the display modulation layer is an array of LCD pixels, LED drive values may drive the LEDs to emit light having particular luminous intensities, and LCD pixel drive values may drive the LCD pixels to assume particular transmissive states.
The time it takes for an LCD pixel to switch from one transmissive state associated with one LCD pixel drive value to another transmissive state associated with another LCD pixel drive value (i.e. the step response time of the LCD pixel) is typically much greater than the time it takes for an LED to switch between ON and OFF states, or from one luminous intensity level associated with one LED drive value to another luminous intensity level associated with another LED drive value (i.e. the step response time of the LED). For example, the step response time of an LCD pixel can be on the order of a few milliseconds or higher, whereas the step response time of an LED can be much shorter, for example, 10 to 100 nanoseconds. In some cases, it may take more than one frame period for an LCD pixel to transition from a current transmissive state to the desired transmissive state associated with a particular drive level.
The response characteristics of the LEDs and/or LCD pixels may affect the displayed image, for example, resulting in image blurring, flickering, halos or other visual artifacts that may be perceived by the viewer. Some references describing attempts to address image display issues of types that may be associated with the response characteristics of the backlight and/or LCD pixels in a display are:                United States Patent Application Publication No. 2007/0285382 published 13 Dec. 2007 (Feng);        United States Patent Application Publication No. 2007/0103424 published 10 May 2007 (Huang);        United States Patent Application Publication No. 2008/0042968 published 21 Feb. 2008 (Oh);        United States Patent Application Publication No. 2007/0057900 published 15 Mar. 2007 (Huang);        United States Patent Application Publication No. 2008/0079686 published 3 Apr. 2008 (Cemasov);        United States Patent Application Publication No. 2005/0248553 published 10 Nov. 2005 (Feng et al.);        U.S. Pat. No. 7,173,599 issued 6 Feb. 2007 (Nishimura);        United States Patent Application Publication No. 2006/0125771 published 15 Jun. 2006 (Inuzuka et al.);        U.S. Pat. No. 7,312,777 issued 25 Dec. 2007 (Miyata et al.); and        United States Patent Application Publication No. 2008/0111835 published 15 May 2008 (Hu).        
There is a general desire to provide displays which provide a high-quality viewing experience. There is a general desire to provide systems and methods for ameliorating and/or overcoming image display issues related to the response characteristics of the backlight and/or display modulation layer in a display.